Many programming languages offer a wide variety of web servers and development frameworks for different target groups and project types. In the C# world, ASP.NET Core is generally considered the default choice. To broaden this perspective, this article provides an overview of all currently available web servers and development frameworks in the .NET ecosystem.
We will highlight active development projects that enable the hosting of web applications. Add-ons for ASP.NET Core (such as FastEndpoints) are not covered in this overview. Furthermore, no overall rating or ranking is given - the frameworks are described in alphabetical order. Nevertheless, there is an overview table for easy comparison of the projects presented here.
For clarity, we group the projects according to their activity into actively developed and no longer active projects. We will only examine the group of actively developed projects in detail.
Table of Contents
Actively Developed Servers
This section covers all actively maintained and supported web server frameworks for .NET.
ASP.NET Core
Based on libuv, the library that significantly influenced Node.js, Microsoft modernized the aging ASP.NET with ASP.NET Core starting in 2014. Later, Kestrel, a .NET-based engine, was added as a modern foundation. Minimal APIs marked ASP.NET Core’s arrival in modern web development in 2021.
From both a functional and technical perspective, ASP.NET Core leaves little to be desired: it supports various API styles, common middleware such as compression and caching, and implements all common authentication mechanisms. ASP.NET Core is the only framework in this list that offers native support for HTTP/2 and HTTP/3. Native, and therefore first-class, support for features sometimes depends on Microsoft's positioning of its own solutions – for example, ASP.NET Core does not provide native support for server sent events (SSE) because Microsoft promotes its in-house solution, SignalR, instead. Since there are many dependencies to consider for such a widely used framework, new technologies are sometimes only supported after a delay, as can be seen in the example of Minimal APIs. In the end, almost all use cases can be implemented with ASP.NET Core, even if this often requires the use of community guides and tutorials.
Microsoft sees ASP.NET Core less as a framework that can simply be added to a .NET project and more as a standalone ecosystem. This prevents use cases such as embedding web servers in other applications such as MAUI or WPF apps. It also links the use of ASP.NET Core with other dependencies such as configuration handling, which steepens the learning curve.
In 2016, Microsoft focused on optimizing performance, resulting in ASP.NET Core being the fastest web server framework in TechEmpower Framework Benchmarks Round 13. While other frameworks have been further optimized, Microsoft has rested on its laurels, with the platform achieving 79% and Minimal APIs 64% of maximum performance in TechEmpower's latest JSON test. This means that ASP.NET Core is still very fast, but no longer the leader.
In essence, ASP.NET Core is the best choice for teams building production-grade web services that require a mature ecosystem, long-term support, and seamless integration with cloud and enterprise infrastructure.
GenHTTP
GenHTTP was originally developed as an application server in 2008 and underwent a fundamental modernization in 2019. Similar to most frameworks on this list, it focuses on providing a simple and fast developer experience.
GenHTTP can be used to host REST web services in various styles, web sockets, server-sent events, static files, and single-page applications. After ASP.NET Core, this framework offers the widest range of functions and also includes, for example, a module for reverse proxies, server-side cached content, or mTLS authentication.
GenHTTP aims to make project development as easy as possible for developers, while also offering extensive customization options. For example, the framework allows the addition of further serializers or compression algorithms that are permanently integrated into other frameworks. This results in greater complexity and a slightly steeper learning curve, but GenHTTP generally hides this well from its users. There is support for dependency injection, but built on top of the framework and not as native as in Wired.IO.
Similar to ASP.NET Core, GenHTTP allows the underlying engine to be exchanged – projects can also be hosted on Kestrel and, conversely, GenHTTP functionalities can be used in ASP.NET Core via adapters. This enables support for HTTP/2 and HTTP/3 via Kestrel, even if the internal engine itself only supports HTTP/1.1. In addition, there is an adapter for Wired.IO.
GenHTTP requires .NET 8 or higher. Support is provided via GitHub or a Discord community, but the website also offers commercial support options.
In TechEmpower's FrameworkBenchmarks, GenHTTP achieves 46%, one of the lower results on this list.
To summarize, GenHTTP is well suited for developers who want a flexible, embeddable web server framework with a broad feature set and full control over protocol- and infrastructure-level behavior.
Sisk
Sisk was created by Brazilian developer Adão with the first release appearing around 2022. It focuses on a declarative, dependency-free style and thus on a simpler developer experience than ASP.NET Core.
Sisk has a strong focus on enabling developers to quickly deploy web applications. The documentation is very clear and practical. Those who can live with the range of functions will quickly be able to set up lean and clear projects, including websockets and server sent events. Advanced features such as JWT authentication, caching directives, native dependency injection or SSL headers are missing. The server framework is actively being developed, with several commits per week. Support outside of the GitHub repository is not provided.
Sisk requires .NET version 8 or higher; .NET Standard and the .NET Framework are not supported. As with the other frameworks, only HTTP/1.1 is implemented.
There is an ongoing effort to provide a new engine implementation (cadente) with improved performance. For now, Sisk achieves around 5% in TechEmpower's FrameworkBenchmarks, 43% with the new engine, making it the slowest server on this list.
To sum up: Sisk is a good fit for small, focused web services where simplicity, minimal dependencies, and a declarative programming model are more important than a comprehensive feature set.
SimpleW
Started in 2023, SimpleW provides controller style REST APIs and also supports websockets and server sent events. It shows a lot of activity from the second half of 2025 on, making it an actively developed project.
Similar to GenHTTP and Sisk, SimpleW aims to enable developers to quickly develop web applications with minimal code. However, in direct comparison to these frameworks, it may provide a less clear API and documentation - which is likey due to its strong integration with the controller pattern. For the functionality being provided, SimpleW has a pretty small code base, alas advanced features such as Open API support or SSL headers are missing. In contrast to the other frameworks in this list, SimpleW has explicit support for telemetry.
As with GenHTTP and Sisk, SimpleW runs on .NET 8 onwards. Support outside of the GitHub repository is not provided, and only HTTP/1.1 is implemented.
Originally based on NetCoreServer, SimpleW is currently undergoing efforts to add its own engine, yielding impressive 71% in TechEmpower's FrameworkBenchmark, and therefore being faster than Minimal APIs on ASP.NET Core.
In essence, SimpleW is suitable for developers who prefer a controller-based programming model and want to build REST APIs quickly while retaining strong performance characteristics.
Unhinged
Unhinged is an experimental HTTP/1.1 webserver engine that, while being nowhere near production-ready, shows how .NET web servers could once again be among the fastest servers in the future. In TechEmpower's FrameworkBenchmark, Unhinged achieves 98.4%, allowing it to claim the third place overall. It will be interesting to see how this development will influence other web server frameworks, including ASP.NET Core itself.
In essence, Unhinged is primarily of interest to developers exploring the performance limits of HTTP servers in .NET and is not intended for building production web applications.
Watson
Watson has been around for several years, is part of the .NET Foundation and receives large commits approximately once a year.
While providing high-level features such as Open API integration, Watson positions itself more as a low level HTTP server library than a web service development framework, making it more comparable to Unhinged and Wired.IO. For example, Watson expects you to implement chunked transfer encoding of responses yourself, features such as JWT authentication, CORS or compression are not provided and expected to be implemented by the user. Watson uses http.sys to listen for incoming HTTP requests on Windows, providing a managed wrapper around this OS functionality. For Unix, there is Watson.Lite with no dependency on http.sys.
In contrast to other frameworks on this list, Watson supports a wide variety of target frameworks, from .NET 4.6.1 to netstandard2.1 and .NET 10, making it a possible choice for legacy projects or exotic use cases such as embedding into a Unity game. As with the other frameworks, Watson only supports HTTP/1.1. Support outside of the GitHub repository is not provided.
Watson is not included in TechEmpower's FrameworkBenchmark.
In summary, Watson is a reasonable choice for scenarios that require low-level access to HTTP primitives, broad framework compatibility, or integration into legacy or embedded applications.
Wired.IO
Started in December 2024, Wired.IO is one of the youngest frameworks on this list. It provides full control in handling HTTP requests at a low level, up to replacing the HTTP parser with a custom one. In contrast to the other frameworks on this list, Wired.IO provides first-class support for dependency injection and logging.
While Wired.IO allows low-level interactions such as directly writing a HTTP response, it provides several mechanisms to achieve routing, middlewares, JSON serialization, hosting static files and single page applications, making it a modern, production-ready framework for webservice development and a potential replacement for Watson. The documentation is clear and up to date. High level features such as Open API integration or CORS are not provided, but can be seamlessly added using an adapter that allows to plug in GenHTTP modules into a Wired.IO application.
Support is provided via GitHub and a Discord community. Wired.IO requires at least .NET 9, and provides a HTTP/1.1 implementation.
In TechEmpower's FrameworkBenchmark, Wired.IO achieves 76%, with a marginal difference to ASP.NET Core and way faster than Minimal APIs.
In conclusion, Wired.IO is well suited for advanced use cases that require fine-grained control over HTTP request handling while still benefiting from modern abstractions such as dependency injection and logging.
Summary
The following tables provide a high-level comparison of the frameworks discussed above. They are not intended as a ranking, but as a compact reference to highlight differences in scope, focus, and capabilities.
The criteria are intentionally broad and reflect typical requirements when building web services in .NET. Not all criteria are equally relevant for every framework, as some projects deliberately focus on low-level control or a narrow set of use cases rather than comprehensive feature coverage.
| Criteria | ASP.NET | GenHTTP | Sisk | SimpleW |
|---|---|---|---|---|
| Webservices | 🟢 | 🟢 | 🟢 | 🟢 |
| Websockets | 🟢 | 🟢 | 🟢 | 🟢 |
| Server Sent Events | 🔴 | 🟢 | 🟢 | 🟢 |
| Static Files | 🟢 | 🟢 | 🟢 | 🟢 |
| SPA Support | 🟢 | 🟢 | 🔴 | 🟢 |
| Infrastructure Services | 🟢 | 🟢 | 🟡 | 🟡 |
| Dependency Injection | 🟢 | 🟡 | 🔴 | 🔴 |
| Documentation | 🟢 | 🟢 | 🟢 | 🟡 |
| Performance | 🔵🔵🔵 | 🔵🔵 | 🔵 | 🔵🔵🔵🔵 |
| Embeddable | 🔴 | 🟢 | 🟢 | 🟢 |
| AoT | 🟡 | 🟡 | 🟢 | 🟡 |
| HTTP Versions |
1.1, 2, 3
|
1.1 (2, 3) |
1.1 |
1.1 |
| Frameworks | >= dotnet6 |
>= dotnet8 |
>= dotnet8 |
>= dotnet8 |
| Last Release | 12/2025 |
12/2025 |
12/2025 |
11/2025 |
| GitHub Stars | 37.5k |
242 |
198 |
81 |
| Criteria | Unhinged | Watson | Wired.IO |
|---|---|---|---|
| Webservices | 🔴 | 🟢 | 🟢 |
| Websockets | 🔴 | 🔴 | 🟡 |
| Server Sent Events | 🔴 | 🔴 | 🔴 |
| Static Files | 🔴 | 🟡 | 🟢 |
| SPA Support | 🔴 | 🔴 | 🟢 |
| Infrastructure Services | 🔴 | 🔴 | 🟡 |
| Dependency Injection | 🔴 | 🔴 | 🟢 |
| Documentation | 🔴 | 🔴 | 🟢 |
| Performance | 🔵🔵🔵🔵🔵 | - |
🔵🔵🔵🔵 |
| Embeddable | 🟢 | 🟢 | 🟢 |
| AoT | 🟢 | 🟡 | 🟢 |
| HTTP Versions | 1.1 |
1.1 |
1.1 |
| Frameworks | >= dotnet9 |
any |
>= dotnet9 |
| Last Release | 11/2025 |
12/2025 |
12/2025 |
| GitHub Stars | 3 |
457 |
35 |
Legacy Servers
This section covers web server frameworks that are no longer actively developed. Legacy frameworks may still be viable for maintaining existing systems, but are generally not recommended for new projects due to limited development activity and ecosystem support.
EmbedIO
Embedio was one of the first lightweight web server frameworks for C#. Accordingly, the library has over 1600 stars on GitHub and is still used in legacy software or even for new, simple projects. The last major changes to the server date back to March 2020, and there are increasing difficulties with its use in current technologies. As the engine uses the deprecated HttpListener underneath, EmbedIO ranks 497th out of 520 framework in TechEmpower's FrameworkBenchmark, with only 0.5%.
NetCoreServer
NetCoreServer is a socket library that can also be used for serving HTTP requests. Since end of 2022, there has not been any meaningful activity. NetCoreServer achieves 53% in TechEmpower's FrameworkBenchmark.
Nancy
Nancy was one of the oldest frameworks, with its first release in 2010. It has officially been archived in 2021. In TechEmpower's FrameworkBenchmark, it achieved 14%.
Conclusion
The .NET ecosystem is often perceived through the lens of ASP.NET Core - and for good reason, given its maturity, breadth, and strong industry backing. However, as this overview shows, ASP.NET Core is only one of several viable approaches to building web-facing applications on .NET.
Beyond the mainstream, the ecosystem offers a diverse range of web servers and frameworks that address different priorities: from minimalism and embeddability to low-level control and experimental performance research. These alternatives may not aim to replace ASP.NET Core, but they expand the solution space and enable use cases that would otherwise be difficult or impractical to address.
Choosing the right framework is therefore less about finding a universal “best” option and more about understanding the trade-offs each project makes. By looking beyond the default choice, developers can better align their tools with the specific technical and organizational constraints of their projects - and fully leverage the versatility of the .NET platform.
Cover picture by Markus Winkler
Top comments (8)
Big ASP.NET user here, changed to java for better ecosystem in IoT applications, nice to see that there are quite a few options for C#, what about AoT support?
Edit: nvm, saw it on the comparison table.
Would be interesting to see more about app size too!
I think there should be an additional post on app size, memory usage, latency, startup time etc. which would give an interesting view. Maybe somewhere in the future.
Would love to see how some of the lower level alternatives behave in embedded Linux systems with very limited hardware, had a not so good experience with asp net a few years ago.
Well even with AoT you will have a garbage collector that will apply some pressure to your device, so it depends on the sizing of the hardware. ASP.NET adds some additional overhead and dependencies onto this, such as specific packages that need to be installed. It's obviously positioned as a full blown server framework.
Besides Unhinged and Watson, all of the frameworks above use the .NET socket API to listen for requests, so their performance characteristics in your scenario will be roughly the same. You might want to avoid the reflection layer that Sisk, GenHTTP and SimpleW add - so your best bet would be Wired.IO.
From working with dotnet apps on such hardware, I would actually expect to get a satisfying performance using a natively compiled wired app.
I was inclined towards this Unhinged solution, did a quick test and I am impressed on how lightweight is feels, looking at its source code set me back a little bit, not very familiar with lower level C#. I'll keep an eye on it, needs API maturity.
I'll check Watson and Wired.IO another time, thank you
Great overview! Love how it highlights lightweight C# web frameworks beyond ASP.NET, perfect for devs seeking performance, simplicity, and modern architectures 👍
Great analysis, I've used some of the listed frameworks and finally see a post for C# comparing them out, glad to learn that there is life outside asp net core :)
ASP.NET has support for SSEs as of .NET 10. SignalR not required.